(a) Field of the Invention
The present invention relates to an apparatus and method for controlling a clutch within a hybrid vehicle, and more particularly, the present invention relates to an apparatus and method for controlling a clutch within a hybrid vehicle that sets a limited torque to the motor torque and converts a mode of the hybrid vehicle using a slip of a Dual Clutch Transmission (DCT), when converting a driving mode of the hybrid vehicle, which a DCT is mounted within, from an Electric Vehicle (EV) driving mode to a Hybrid Electric Vehicle (HEV) driving mode.
(b) Description of the Related Art
A hybrid vehicle is a vehicle that uses two or more different types of power sources. Generally, the hybrid vehicle is driven by an engine that obtains a driving torque by burning fuel and a motor that obtains a driving torque from battery power. A hybrid vehicle may be formed in various structures that use an engine and an electric motor as a power source. A vehicle that uses an electric motor to directly transfer engine mechanical power to a wheel and is operated using power from a battery is called a parallel hybrid vehicle. Further, a vehicle that drives an electric motor or charges electric power to a battery by converting engine mechanical power to electrical power using a generator is called a series hybrid vehicle. Within the parallel hybrid vehicle, an engine and a motor may be connected by an engine clutch, a DCT may be connected to a shaft of the engine and the motor, and a transmission may be connected to the DCT.
A major driving mode of the hybrid vehicle includes an EV mode, in which an engine clutch is uncoupled and is only driven with a motor, an HEV mode, that drives an engine and a motor together coupled with the engine clutch, and a slip driving mode, that may not completely couple the engine clutch within the HEV mode and that transfers an engine torque when rotation speeds of the engine and the motor are different. Particularly, conversion between an EV mode and an HEV mode is a major function of the hybrid vehicle and may have an influence on driving performance, fuel consumption, and power performance of the hybrid vehicle.
When a hybrid vehicle starts, a motor is driven by power charged within a battery and a driving torque generated within the motor. Further, a DCT is completely coupled within the hybrid vehicle to transfer power to a driving shaft. However, to convert from an EV mode, when a motor and a DCT are coupled, to an HEV mode, a coupling force of the DCT is reduced to generate slip of the DCT and acceleration linearity (e.g., acceleration adjusts linearly) may decrease. Further, acceleration linearity may even decrease when a motor and an engine synchronize and a wheel torque decreases.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.